A 6-day-old boy is brought to the emergency department for inability to feed for 12 hours. His parents report that the infant has been unable to open his mouth and has held his hands clenched all day. The infant was delivered at home by the grandmother. The mother had no access to prenatal care but says that the pregnancy was uncomplicated. The mother immigrated to the United States 6 years ago. Physical examination shows increased muscle tone throughout, arching of the back, and dorsiflexed feet. The umbilical cord is covered with a clump of soil. The mother says that it is customary in her village where she grew up to cover the umbilical stump with dung to speed cord separation. In addition to hygienic umbilical cord care, which of the following is the most effective strategy to prevent this condition?